The Heat editor-in-chief, Mark Frith, is leaving Bauer Consumer Media after more than 10 years developing and overseeing the celebrity magazine phenomenon.

Frith will leave Heat and Bauer in mid-May to concentrate on fulfilling a long-held ambition to write a book, having recently signed with publisher Ebury Press.

His departure from Heat comes two months after Bauer bought the title along with Emap's other consumer magazines and its radio business.

Frith joined Heat in December 1997 as deputy editor when it was still in development and known as Project J.

He became editor in 2000 when Heat was struggling immediately after its launch and reinvented it as a unisex entertainment title and women's celebrity weekly that became a publishing sensation.

Heat's success under Frith, with sales rising from 65,000 to 590,000, galvanised the UK consumer magazine market and came to define a decade in which the media and readers became obsessed with celebrity culture.

Frith has won every major British publishing award, including PPA editor of the year twice and, in 2005, the BSME Mark Boxer Award for special achievement in UK magazine publishing.

He said: "Taking Heat from sales of 65,000 a week to over half a million has been an exhilarating experience. The Heat team is truly exceptional and I wish them all the best for the future.

"I'm extremely excited about the book and look forward to a brand new challenge when I've finished it."

Frith's book, to be called The Celeb Diaries, will see him spill the beans on his experiences with celebrities such as Victoria and David Beckham, Jude Law, Amy Winehouse, Take That, Geri Halliwell, Jonathan Ross and Ewan McGregor, who memorably described Heat as a "dirty, filthy piece of shit".

The deal with Ebury Press, publishers of Piers Morgan's The Insider and Don't You Know Who I Am, was brokered by the London office of international talent agents William Morris.

Jake Lingwood, the Ebury Press publisher, said: "The celebrity culture that Heat kick-started has become so dominant that the inside track on how it came about, what deals were struck, and who said what to whom, is a brilliant media story."

The Celeb Diaries will be published this autumn and is one of the publisher's priority titles for Christmas 2008

Frith began his journalism career at Emap's Smash Hits in 1990, and in 1994, at the age of just 23, was appointed editor before leaving for Sky Magazine in 1996. A year later, he joined Heat.

As well as editing Heat, Frith has presented BBC3's Liquid News.

Julian Linley, editor of heatworld.com and a former deputy editor of Heat, will become acting editor, although he has said he does not want the job full time.

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